A Crossed Match
by Alexandra Cantarella
Summary: Sasuke is type AB and Sakura is type O. It's funny how blood types can define you. SasuSasku/ONESHOT/Rated T just to be safe.
Disclaimer: All rights to the Naruto characters reserved to Masashi Kishimoto-sensei. I only own the plot. Even the medical jargon here were grasped from my lessons in Medical Technology.

 _/krôs maCH/_

 _verb_

 _def: to test the compatibility of (a donor and a recipient's blood or tissue)_

A CROSSED MATCH

"BAA-CHAAAAAN!"

A loud, screeching voice broke the silence of the early Konoha air. Birds from nearby trees flew from their roost and nests, frightened by the sheer volume of the sound. A blonde woman with breasts too unnatural for her body and a face too young for her age almost jumped out of her skin as she was jolted out of her slumber.

Bleary, hazel eyes blinked around dazedly at the towering stacks of paperwork on her desk and an equally high pile of sake bottles littered in one hidden corner of the room as they tried to focus on the source of the sound. It took the woman a few moments to register the derogatory endearment and its equally obnoxious source.

 _If this brat's father is compared to lightning for his speed, then it is just fitting for the son to be like thunder: everyone in the whole fucking village and possibly other villages in the Fire Country can hear him before he even arrives._

Growling, the Godaime Hokage of Konohagakure picked up the nearest bottle of sake and threw it with shaky, yet sharp precision towards the door.

It was also that very moment that the entrance to her office opened and a blur of blinding yellow and similarly sickeningly flashy orange came barging in. Years of training and shinobi reflexes saved the offender from the Hokage's wrath and possibly, death by a flying sake bottle.

"WHAT WAS THAT FOR?!"

The blond shinobi skidded to a halt in front of the desk, glaring. He was panting and heaving. He was covered in bruises and cuts that didn't seem critical and he stank strongly of blood, sweat and dirt—something not very pleasing to wake up to.

"What the hell are you doing summoning the apocalypse at this time of the day, Naruto?" Tsunade growled, her eyes narrowing dangerously, a vein popping in her temple in annoyance. She gave him a once over and asked, "Aren't you supposed to be on a mission?"

Once the words were out of Tsunade's mouth, the blond boy's usually mischievous expression twisted into a panicked frown. This stopped the busty woman's incoming punch.

"That's why I came here, Tsunade baa-chan," Uzumaki Naruto replied, waving his arms around wildly. "We were ambushed on the way back here. Rogue Sound-nins. They got Sakura-chan good."

At the mention of Sakura's name the slug Sannin's ears perked up. The Kyuubi vessel usually exaggerates his accounts, but today, Tsunade could see wild fear in Naruto's eyes.

"How bad is she?"

"I don't know!" Naruto wailed. "One second, Sakura-chan, the teme and I are fighting the rogues and we were doing fine. Sakura-chan was holding her own really great against the medi-nin of the group and she was making craters and holes here and there but then, she suddenly turned very white and then, and then she—she started to sway like she was drunk or dizzy or whatever, and—and she just fell down. She just fell down like that!"

This surprised Tsunade. Sakura was by no means invincible and enduring like others would like to believe, being the disciple of one of the three legendary Sannins and all. But then again, that does not mean that her stamina is low, considering she has excellent chakra control, therefore has an impeccable sense of balancing her chakra reserves. Long hours of training under her tutelage had honed the girl's endurance as well. It is not impossible, however for Sakura to use up her reserves, as the girl, no matter how brilliant, intelligent and practical she is, is very generous and selfless in nature to the point of stupidity.

"Chakra depletion?" she asked her fellow Sannin's student.

"Don't think so," Naruto shook his head, watching as Tsunade prepares to leave her office. "We didn't get much fights going to Ame. She's been taking good care of herself if that's what you're asking. Oh, yeah, she's been getting black and blue since we retreated."

Tsunade's eyes went wide.

"What?!"

"I said—"

"I heard you, you baka!" the Hokage seethed, smacking the boy upside the head. "Why didn't you tell me earlier?!"

"ITAI!" Naruto whined. "I told you—I told you!"

"Where is she?"

Naruto cringed at the urgency in Tsunade's voice. He sensed something serious is going on and he's scared to find out what.

"The teme brought her to the hospital," he informed her.

"What's her condition?"

"I don't know," Naruto shrugged. "I ran here as soon as we reached the gates."

Tsunade exhaled through clenched teeth.

 _Baka._

The doors to the Konoha Hospital slammed open, admitting the Fifth Hokage with a bewildered Naruto on her heels. The hospital was a beehive of activity as per usual, but everyone halted their respective tasks in order to greet their Hokage and administrator. With only a single nod as her acknowledgement, Tsunade marched up to the receptionist.

"Haruno Sakura," she all but growled. "Where is she?"

"Ah, ohayo, Tsunade-sama..."

The receptionist cowered at the impatient glower sent her way by the blonde woman.

"Right, Haruno-san," she stammered. "She is at the ICU right now. Uchiha-san brought her in and she seems critical. Shizune-san was called to handle her case."

The Godaime only grunted in reply and once again nodded before scurrying to the ICU.

It was no surprise that they found Uchiha Sasuke brooding like a cloud outside the ICU.

It was not a secret that after the Fourth Shinobi World War, the last Uchiha and the slug Sannin's apprentice tried to repair the shaky bonds between them that were thin and worn yet remained intact. Despite Sakura's unwavering love and devotion towards Sasuke, the two had so much history hanging between them, including attempting to kill each other at one point. Both were wary of each other, walking around on eggshells the entire time.

Sasuke was on probation as part of his sentence for the crimes he committed against the village. He was given leniency considering his role as the unexpected hero of the war. Sakura was one of those who spoke for him and being a respected combat-medic in her own right and also, her influence as Tsunade's disciple contributed to her teammate's merciful penalty.

During that period, it was Sakura and Naruto who helped the lone Uchiha survivor adjust to the village. Sasuke and Naruto never really severed the bonds between the two of them and in just a matter of weeks the two rivals already had the training grounds damaged beyond reasonable repair due to their intense sparring sessions. The banters and the insults between the two were thrown like training shurikens. It was as if the whole fiasco did not happen and it was like the two were never separated.

It was different for Sakura and Sasuke, though. Despite her unyielding affection for the Uchiha, Sakura is still hung up on her guilt for trying to kill Sasuke. Despite what everyone else believes, Sakura was the one who had the killing intent on that day in the Land of Iron. Sasuke, already in his deranged state of mind, was merely acting out of self-defense in the best way he knew how. Sasuke, on the other hand, was as awkward and as self-deprecating as ever. He had no idea how to approach the situation with Sakura and ended up snubbing her and avoiding her most of the time.

But as all clichéd love stories go, they eventually came around. It was a slow burn for them. It was an impatiently, infuriating dance, but soon, the pink-haired medic found it in herself to familiarize herself with all of the Sharingan-wielder's quirks and grunts and unspoken sentiments. She gradually saw past the carefully built walls that Sasuke barricaded himself with. Sasuke, to his credit, became more open to Sakura and decided to make an effort to be kinder towards her, perhaps out of guilt and remorse. Nevertheless, it was not after two years since Sasuke returned that they can be seen walking towards the training grounds together, sparring together, eating at Ichiraku's _without_ Naruto. It was only when the Godaime Hokage herself found Sasuke lingering about the hospital thirty minutes past eleven—coinciding with her pink-haired apprentice's late shift—that she knew things between the two were different. She saw Sakura getting out of the hospital, weary and slouching, carrying a medic bag that is more than her deceptively delicate form can handle. Sasuke met her halfway, took the bag from her—despite her protests—and placed a firm, possessive and protective hand on her back and walked her home. It was just that moment that Tsunade realized that the Uchiha District is situated opposite of the path where Sakura's apartment stands.

Now, looking at the way Sasuke's jaw clenched as he stood rigidly against the stark white walls of the hospital, the Godaime could only imagine how devastated the young man would be if something bad would happen to Sakura at this very moment.

Hell, even she wouldn't know how many forests she'd clear and how many mountains she'd flatten and how many sake bottles she'd empty if something were to happen to that annoying pink-haired brat she fostered.

Sasuke didn't even look up to acknowledge the arrival of his best friend and the Hokage. He just kept his hard gaze to the floor.

"Uchiha," Tsunade barked. This got the raven-haired shinobi's attention. He gave a nod in acknowledgement.

"Teme!" the loud voice reminded Tsunade of the blond ninja that accompanied her. "How is Sakura-chan?"

"Hn," Sasuke grunted in his usual irate monotone, only now, Tsunade can sense that his tone sounded more anxious than annoyed. "Dobe."

"Uchiha," she repeated. "Give me damn straight answers or I swear I will launch you straight through the Hokage Mountain."

"Hn."

Taking this as her cue to interrogate, the fifth Hokage began.

"First, tell me what _exactly_ happened out there," she demanded. " _Someone_ did not actually elaborate how critical the situation was."

"Oi!" Naruto protested.

"We were ambushed in the border near Sound," Sasuke supplied. "Rogue ninjas. Naruto and I were fighting them and Sakura went to evade and possibly to incapacitate the group's medic. We were doing fine until we saw Sakura stumbling. There were no visible critical wounds on her body. Just one on her arm and it looked like it came from a senbon needle. She turned very pale and just fell. When we were travelling back here, she was shaking and bruises started to appear on her body. No specific pattern, just random."

"And how is her chakra?" Tsunade queried.

"Weak," Sasuke answered bluntly. "Faint."

With all the information given by Sasuke, Tsunade can easily distinguish what ails her apprentice. It seems like Naruto is having the same train of thought. After all, he had been witness to similar cases that Sakura had handled.

"Baa-chan," he started. "Could it be that Sakura-chan is—"

"It's poison."

The group turned their heads to see a dark-haired medic exiting the emergency room.

Shizune nodded her greeting to the two shinobi before turning to face her mentor.

"I was about to send someone to fetch you, Tsunade-sama," she bowed. "But it seems like Naruto did it for me. Sakura-chan's condition is critical."

"How is she?" Tsunade asked.

"She needs immediate blood transfusion," the Hokage's other apprentice replied.

"What?!" the fiery-tempered Hokage exclaimed. At the sound of 'blood transfusion', the two boys of Team 7 leaned in closer, their eyes wide in shock and disbelief.

"How the fuck can poison lead to something as a last-minute resort technique such as blood transfusion?" Tsunade boomed.

"We had it extracted from her system and had it examined in the lab," Shizune explained. "It was a new strain of poison that infects the bloodstream. Once it enters the body, it destroys her red blood cells, cutting off the oxygen in her body, as it goes with the flow of her circulation. The white blood cells are now greater in number than the red cells, giving her bruises that is similar to the symptoms of leukemia."

"And why would you need transfusion if the poison is extracted?" Sasuke snapped.

"We already isolated the infected deoxygenated blood cells and we can't risk that circulating through the heart," Shizune continued. "Therefore, her oxygenated blood can't be replenished until a healthy amount of whole blood can be transfused into her system to keep it running so that her organs and her entire body won't suffer from a lack of oxygen while we stabilize her. We have already supplied her with blood expanders and erythropoietin to prevent her from going into hypovolemic shock. But these only did enough to supply her body with enough oxygen for her organs to cells to synthesize for the functioning of her organs as well as get her RBC production running as well. Her RBC regeneration is slower than expected, so we have to resort to transfusion to help her body recover as quickly and as normally as possible. After the transfusion, she'll be safe."

"Well, then get her something from the phlebotomy section immediately," Tsunade ordered.

"That's just it, Tsunade-sama," the medic informed. "Sakura-chan is type O. You know how common and in demand rtype O is. We're kind of out of type O as of the moment."

"Well, fuck," Tsunade sighed impatiently.

"What?" Naruto questioned after wrapping his head around the medical jargon that Shizune and Tsunade had been spewing. "What's happening, Baa-chan? It can't be good if you say 'fuck'."

"Sakura can't get her transfusion today," the Hokage replied.

"What do you mean she can't get her blood transfusion today." Sasuke stated more than asked. "She needs blood doesn't she? Take mine or the dobe's."

"It's not how it works, Uchiha," Tsunade gritted out irately. "Unless you're blood type O, her transfusion will have to wait. We have to stabilize her for the meantime and work to avoid her system from collapsing to lack of oxygen."

"Then make it work, damn it!" the Uchiha heir snapped back, his eyes wild and his voice held a furious edge contrary to the blasé tone he was accustomed to. "You're a medic, you're a Sannin, she's your apprentice, and you can make it work!"

"Listen here, you brat," Tsunade growled, clearly annoyed with the dark-haired shinobi. She only had to pray that she had enough control so that Sakura won't wake up to a mangled Uchiha. "I'll give you a little crash course about blood. See here, there are four types of blood: type A, type B, type AB and type O. To make it less confusing for you, I'll emphasise on Sakura's blood type and what would happen if we transfuse her system with yours. Sakura is type O. And type O is the easiest blood to donate. It matches with almost every blood type in the world unless your genes carry both dominant blood types, the A and the B. But that seldom happens. The O is recessive and most blood types carry a mix of the dominant types and the recessive. That's why the type O blood is called the "Universal Donor". It can match up to almost any blood type. Are you still following?"

"Hn."

"Good," Tsunade continued. "Now, you, Uchiha, from what I've heard from Sakura, have blood type AB. Your kind of blood type is the "Universal Recipient". Since it is a mix of A and B and possibly one of those types are a hybrid with O, you can pretty much receive any blood type. See how I can't let you donate blood to Sakura?"

Tsunade saw understanding settle in Sasuke's eyes. For emphasis, Tsunade concluded, "Your blood type is extremely opposite with Sakura. Her blood can supply everyone and yet, she can't receive just any type of blood. Your blood can receive any type of blood, but you can't donate to anything, most especially to someone with blood type O. Transfusions with incompatible blood types can be dangerous, if not fatal."

At the Uchiha's repressed downcast expression, Tsunade's countenance softened for a bit. This is the boy who lost so much in life and to lose another person important to him without doing anything to help would be a very huge blow to his psyche, if not to his pride.

"I know you mean well, Uchiha," she calmly soothed, placing a hand on his shoulder and not missing the grimace at the implication of being a _benevolent sap._ "But you can't help her this time, not with the circumstances."

Regaining her snarky tongue, the Hokage then tapped his shoulder rather sharply. "And get the hell out of my way and brood somewhere, brat. Let us handle Sakura and she'll be annoying you in no time."

And with that, she barked orders at Shizune to find someone who is blood type O _immediately_ and for someone to bring her a bottle of sake.

It's mentally and physically taxing to deal with an emotionally-constipated but obviously smitten ex-Avenger, a banged up kunoichi, and a loud, worried knuckleheaded ninja, after all.

 _It's too early in the morning for this kind of shit,_ Tsunade thought as she took a swig off the sake bottle handed to her.

00000000000000000000000000000000000000000000000000000000000000000000000000000000000

It was later in the morning that they found a very willing donor. Hatake Kakashi was blood type O and was very happy to donate some of his blood to his former student. The two boys of Team 7 nearly wrung their Sensei's neck. If Kakashi had told them earlier, it would have saved them from a lot of stress.

Now, the transfusion had been done and Sakura's condition was stable once more. Her blood is slowly being replenished and it would only be matter of hours before she wakes.

Having nothing better to do, Naruto and Sasuke found themselves loitering about the hospital halls in front of Sakura's room.

"What'cha worried for, teme?" Naruto reassured his best friend and rival. "Sakura-chan's stable and she's going to be fine. She's been through a lot of scrapes like these and to be honest, if anyone's going to survive things like these, it would be Sakura-chan. Believe it!"

"Hn," Sasuke grunted noncommittally. "Urusai."

Inwardly, Sasuke had been relieved to find out that Sakura was all right after the transfusion. It just blows that she was his (teammate, friend, girlfriend?) precious person and he wasn't able to do anything to help her. The irony wasn't lost on him though. It's funny how their blood types really defined who they are as people. It is fitting that Sakura, with her selfless, giving personality would have blood type O; the blood type deemed as the "Universal Donor". She had given so much to him almost without any condition. And here he was, a blood type AB, the "Universal Recipient" who would take so much from her (sometimes, even without knowing it), and selfishly think of his own personal gain. The only time that he could return the favour, he couldn't do it because apparently, they are incompatible.

It's completely funny and insultingly ironic how the universe works, sometimes.

00000000000000000000000000000000000000000000000000000000000000000000000000000000000

"So, Tsunade-shishou told me that you almost forced her to let you be my blood donor," Sakura stated as she and Sasuke strolled by Konoha's shopping district. It was a week after she was released from the hospital. Since the poison had to be completely expelled from her system, she was told ( _threatened)_ to take it slow and to refrain from stressing herself out.

Sasuke and Naruto—the former more than the latter—had gone to make sure that she doesn't overdo herself.

"Hn," Sasuke muttered, looking away from her. Sakura giggled amusedly at this.

"Hey," she coaxed, tugging at his hand. She released it as soon as she was sure she got his attention. "You couldn't have done anything about it, anyway. Our blood types were just too incompatible to be matched."

"Aa," he replied. "Tsunade explained that to me."

"I know, she told me," Sakura beamed teasingly. "But it was sweet how you tried to donate blood though you're type AB, Sasuke-kun."

It made Sasuke stop in his tracks.

"I'm not sweet, Sakura," he seethed. Sakura just smiled at him with that sickeningly, annoyingly bright, sweet smile of hers.

"Whatever you say, Sa-su-ke-kun," she replied in a sing-song voice.

A round of comfortable silence passed through them when Sakura began to voice her thoughts.

"How funny, isn't it?" she said. "That of all people, we'd be the ones to have polar opposite blood types."

"Hn." _I know._

"You have the "Universal Recipient" and I have the "Universal Donor"," Sakura mused. "It's funny how the world works sometimes, ne, Sasuke-kun?"

"Aa."

He looks at her with barely suppressed affection in hi onyx eyes. He watches the way her brows furrow just a bit and how her lips pout as she reflects on the coincidences of their blood types and possibly the irony of it all.

"It's just like us, isn't it?" she looks at him. "We're very different. But I guess, that's what makes us work. We balance each other out."

Sasuke wrapped his mind around her reflection. He suddenly saw the irony in a new perspective. The universe does work in strange, effective ways. Fating someone so selfless with someone self-centered can balance them out. It's like pairing someone so loving and giving to someone so desolate and broken and so full of hatred can eventually lead the latter out of his darkness and mend his damaged soul.

After all, the universe is all about balance.

 _We balance each other out._

Sasuke decides that what Sakura says rings true.

"Aa," he agrees. "I guess we do."

* * *

 _A/N:_ Hey guys! So, I made a promise to myself to edit this story and now that I found time, I did! I'm sorry that I have been so inactive lately. College and responsibilities in the school publication were my priorities. I've added only a few details in order to make the procedure for Sakura's situation correct.

HUGE SHOUTOUT TO ONE REVIEWER Troublesome-monkey-dono who pointed out the details that I missed regarding blood loss. Thank you so much!

Anyways, I may have developed an addiction to KDramas and although I fell in love with Descendants of the Sun and W, Moon Lovers: Scarlet Heart Ryeo made an impact on me on a completely different level. It freaking killed me, man. I still have a huge hangover over it. And so, as a drill, my mind decided to form plot bunnies. And yeah, I may be writing a Sasusaku Moon Lovers-inspired AU soon. The plot is almost complete in my head, I already wrote character descriptions it's only a matter of organizing and developing the motivation to write. So, see you, I guess.

Review! I love reading them and constructive criticism is very much appreciated.

-xx


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